JP6209001B2 - Resist composition and method for producing resist pattern - Google Patents

Description

  The present invention relates to a resist composition and a method for producing a resist pattern.

Patent Document 1 discloses the following structural unit:
And the following structural units
A resin consisting of
The resist composition containing the acid generator represented by these is described.
Further, it is known that when a resist pattern is formed from a resist composition by photolithography, a positive resist pattern is obtained when developed with an alkaline developer, and a negative resist pattern is obtained when developed with an organic solvent ( Non-patent document 1).

JP 2008-309879 A

Published by Techno Times Inc. Monthly Display '11 June p. 31

  A resist pattern formed from the above-described resist composition known in the past may not always have a satisfactory resolution.

The present invention includes the following inventions.
[1] A resin containing a structural unit represented by formula (I),
A resin containing a structural unit having an acid labile group and not containing a structural unit represented by formula (I);
A resist composition containing an acid generator represented by the formula (II).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents a saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom. ]
[In the formula (II),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and —CH constituting the alkanediyl group ₂ — may be replaced by —O— or —CO—.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, —CH ₂ — constituting the group may be replaced by —O— or —CO—.
Z ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein the acid generator represented by the formula (II) is an acid generator represented by the formula (IIA).
[In Formula (IIA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and —CH ₂ constituting the hydrocarbon group -May be replaced by -O- or -CO-.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 19 or less. ]
[3] The resist composition according to [1] or [2], further containing a solvent.
[4] (1) A step of applying the resist composition according to any one of [1] to [3] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  According to the resist composition of the present invention, a high-resolution resist pattern can be produced.

In the present specification, "(meth) acrylic monomer" means at least one monomer having a "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

<Resist composition>
The resist composition of the present invention comprises:
Resin (hereinafter sometimes referred to as “resin (A)”), and
It contains an acid generator represented by the formula (II) (hereinafter sometimes referred to as “acid generator (II)”).
The resist composition of the present invention preferably further contains a solvent (E).
The resist composition of the present invention preferably further contains a compound represented by the formula (D) (hereinafter sometimes referred to as “compound (D)”).
The resist composition of the present invention may further contain a basic compound (C).

<Resin (A)>
The resin (A) contained in the resist composition of the present invention is
A resin having a structural unit represented by formula (I) (hereinafter sometimes referred to as “resin (A-1)”) and a structural unit having an acid labile group and represented by formula (I) A resin not containing a unit (hereinafter sometimes referred to as “resin (A-2)”) is included.
Moreover, resin (A) may contain resin other than resin (A-1) and (A-2) which are mentioned later.

<Resin (A-1)>
The resin (A-1) has a structural unit represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”).

[Structural unit (I)]
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents a saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom. ]

Examples of the saturated hydrocarbon group for R ² include an alkyl group, an alicyclic saturated hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Can be mentioned.
The alicyclic saturated hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, Examples thereof include cycloalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, and a norbornyl group.
Examples of the group formed by combining an alkyl group and an alicyclic saturated hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group, a methylnorbornyl group, and an isobornyl group. It is done.

Examples of the saturated hydrocarbon group having a fluorine atom for R ² include an alkyl group having a fluorine atom and an alicyclic saturated hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, 1 , 1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, 1,1,1,3,3,3-hexafluoropropan-2-yl group, Perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2 , 3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, PERF Orobutyl group, perfluoro-tert-butyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2, 2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2 -(Perfluorobutyl) ethyl group, 2- (perfluorooctyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2, Fluorinated alkyl groups such as 3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl group can be mentioned.
Examples of the alicyclic hydrocarbon group having a fluorine atom include a perfluorocyclohexyl group and a perfluoroadamantyl group.

The structural unit (I) is preferably a structural unit represented by the formula (Ia).
[In the formula (Ia),
R ¹ represents a hydrogen atom or a methyl group.
R ³ represents a perfluoroalkyl group having 1 to 4 carbon atoms.
n represents an integer of 1 to 4. ]

Examples of the perfluoroalkyl group for R ³ include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, and a perfluorobutyl group.

The structural unit (I) is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).
[In Formula (I ′), R ¹ and R ² have the same meanings as described above. ]

Examples of compound (I ′) include the following.

  Compound (I ′) can be produced by a known method. For example, compound (I ′) can be produced by reacting a fluoroiodoalkali compound and methacrylate under basic conditions.

  In addition to the structural unit (I), the resin (A-1) preferably includes a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a)”).

[Structural unit (a)]
The acid labile group in the structural unit (a) is a group having a leaving group, and the leaving group is eliminated by contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). means.
Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).
[In the formula (1), R ^a1 , R ^a2 and R ^a3 are each independently formed by an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof. R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]
[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — constituting the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -O- or -S-.

^Examples of the alkyl group represented by R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group for R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.
Examples of the group formed by combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group include the following groups. * Represents a bond with -O-.
The divalent hydrocarbon group preferably has 3 to 12 carbon atoms.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^{a1 to} R ^a3 are alkyl groups in the formula (1), preferably a tert-butoxycarbonyl group), 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- ( And adamantane-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the hydrocarbon group for R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. .
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, and a norbornyl group.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include groups in which one hydrogen atom has been removed from the hydrocarbon groups of R ^{a1 ′ to} R ^{a3 ′} .
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

  The monomer for deriving the structural unit (a) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

  Preferred examples of the (meth) acrylic monomer having an acid labile group include those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. If a resin having a structural unit (a) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

  As a structural unit derived from a (meth) acrylic monomer having a group represented by formula (1), preferably a structural unit represented by formula (a1-1) or a structure represented by formula (a1-2) Units are listed. These may be used alone or in combination of two or more. In this specification, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are represented by the structural unit (a1-1) and the structural unit (a1-2), respectively. The monomer that derives the structural unit (a1-1) and the monomer that derives the structural unit (a1-2) may be referred to as a monomer (a1-1) and a monomer (a1-2), respectively.

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _{k1 ′} —CO—O—, more preferably —O—. k1 ′ is an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the group formed by combining the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and these include the same groups as those described for R ^{a1 to} R ^a3 in formula (1). .
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 preferably has 8 or less carbon atoms, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among these, a monomer represented by any one of formula (a1-1-1) to formula (a1-1-8) is preferable, and any one of formula (a1-1-1) to formula (a1-1-4) is preferable. The monomer represented by is more preferable.

Examples of the monomer (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptan-1-yl (meth). Acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate, 1-isopropylcyclohexane-1- And yl (meth) acrylate. Monomers represented by the formula (a1-2-1) to the formula (a1-2-12) are preferred, and the formula (a1-2-3) to the formula (a1-2-4) or the formula (a1-2-9) The monomer represented by formula (a1-2-10) is more preferable, and the monomer represented by formula (a1-2-3) or formula (a1-2-9) is more preferable.

  When the resin (A-1) includes the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually based on the total structural unit of the resin (A-1). It is 10-95 mol%, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

As a structural unit derived from a (meth) acrylic monomer having an acid labile group, a structural unit derived from a monomer represented by formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”). There is).
[In the formula (a1-5),
R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * — [CH ₂ ] _k4 —CO—L ^a54 —. Here, k4 represents an integer of 1 to 4. * Represents a bond with L ^a51 .
L ^a51 , L ^a52 , L ^a53 and L ^a54 each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ^a51 is preferably an oxygen atom.
One of L ^a52 and L ^a53 is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

Examples of the monomer represented by the formula (a1-5) include the following monomers.

  When the resin (A-1) has the structural unit (a1-5), the content is preferably from 1 to 50 mol%, more preferably from 3 to 45 mol, based on all structural units of the resin (A-1). % Is more preferable, and 5 to 40 mol% is more preferable.

  In addition to the structural unit (I) and the structural unit (a), the resin (A-1) is derived from a monomer having no acid labile group, which will be described later (hereinafter referred to as “structural unit (s)”) And a structural unit derived from a known monomer used in the field may be included.

[In the formula (IIIA),
R ¹¹ represents a hydrogen atom or a methyl group.
Ring W ² represents a hydrocarbon ring having 6 to 10 carbon atoms.
A ¹² represents —O—, ^* —CO—O—, or ^* —O—CO— ( ^* represents a bond to ring W ² ).
R ¹² represents a C 1-6 alkyl group having a fluorine atom. ]

Examples of the hydrocarbon ring of ring W ² include an alicyclic hydrocarbon ring, and a saturated alicyclic hydrocarbon ring is preferable.
Examples of the saturated alicyclic hydrocarbon ring include the following rings.
Ring W ² is preferably an adamantane ring or a cyclohexane ring, and more preferably an adamantane ring.

Examples of the alkyl group having 1 to 6 carbon atoms having a fluorine atom as R ¹² include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and 2,2,2 -Trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, 1,1,1,3,3 3-hexafluoropropan-2-yl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetra Fluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, 2,2,3,3 4,4,4-he Tafluorobutyl group, perfluorobutyl group, perfluoro-tert-butyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group Perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3 , 4, 4, 5, 5, 6, 6-dodecafluorohexyl group, perfluoropentylmethyl group, and perfluorohexyl group. The following groups are preferable.

As the structural unit represented by the formula (IIIA), structural units represented by the following are preferable.
In the above structural unit, a structural unit in which a methyl group corresponding to R ¹¹ is replaced with a hydrogen atom can also be given as a specific example of the structural unit (IIIA).
Among these, a structural unit represented by the formula (IIIA-1) or a structural unit in which a methyl group corresponding to R ¹¹ is replaced with a hydrogen atom is preferable.

In the resin (A-1), the content of the structural unit (I) is preferably 5 to 100 mol%, more preferably 20 to 100 mol%, based on all the structural units of the resin (A-1). It is.
The resin (A-1) is preferably a resin containing the structural unit (I) and the structural unit (a), and more preferably a resin consisting only of the structural unit (I) and the structural unit (a). is there. As the structural unit (a), the structural unit (a1-1) and / or the structural unit (a1-2) is preferable.

When resin (A-1) is resin which consists of structural unit (I) and structural unit (a), these content rates are respectively with respect to all the structural units of resin (A-1).
Structural unit (I); 10-95 mol%
Structural unit (a); preferably 5 to 90 mol%,
Structural unit (I); 15-90 mol%
Structural unit (a); 10 to 85 mol% is more preferable,
Structural unit (I); 20 to 85 mol%
Structural unit (a); 15 to 80 mol% is more preferred,
Structural unit (I); 40 to 75 mol%
Structural unit (a); 25-60 mol% is particularly preferred.

  When the resin (A-1) contains a structural unit (s), a structural unit represented by the formula (IIIA), a structural unit derived from a known monomer used in this field, the total content of these is The amount is preferably 1 to 95 mol%, more preferably 2 to 80 mol%, based on all structural units of the resin (A-1).

Each structural unit constituting the resin (A-1) may be used alone or in combination of two or more. Resin (A-1) which has each structural unit by the content rate as mentioned above adjusts the use molar amount of the monomer which derives each structural unit with respect to the total molar amount of all the monomers used at the time of resin (A-1) manufacture. Can be manufactured.
The resin (A-1) can be produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units.
The weight average molecular weight of the resin (A-1) is preferably 5,000 or more (more preferably 7,000 or more, more preferably 10,000 or more), 80,000 or less (more preferably 50,000 or less, More preferably, it is 30,000 or less.
A weight average molecular weight is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this specification.

<Resin (A-2)>
Resin (A-2) contains the structural unit (a) which is a structural unit having an acid labile group, and does not contain the structural unit represented by the formula (I).
The resin (A-2) further includes a structural unit (s) that is a structural unit derived from a monomer having no acid labile group, a structural unit derived from a known monomer used in the field, and the like. Also good.
The resin (A-2) preferably has a property of decomposing by the action of an acid and reducing the solubility in an organic solvent such as butyl acetate or 2-heptanone.

  The total content of the structural unit (a) contained in the resin (A-2) is usually 10 to 95 mol%, preferably 15 to 90 mol%, based on all the structural units of the resin (A-2). Yes, more preferably 20 to 85 mol%.

When the resin (A-2) includes the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually relative to all the structural units of the resin (A-2). It is 10-95 mol%, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.
When resin (A-2) has a structural unit (a1-5), the content rate is preferable with respect to all the structural units of resin (A-2), 1-50 mol%, 3-45 mol % Is more preferable, and 5 to 40 mol% is more preferable.

[Structural unit (s)]
As the monomer for deriving the structural unit (s), which is a structural unit derived from a monomer having no acid labile group, monomers known in the resist field can be mentioned.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used for the resist composition, the resolution of the resist pattern and the adhesion to the substrate can be improved.

The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When the resist composition is applied to KrF excimer laser exposure (248 nm), high energy beam exposure such as electron beam or EUV (extreme ultraviolet light), the structural unit (a2) having a phenolic hydroxy group as the structural unit (a2) ) Is preferably used. When applied to ArF excimer laser exposure (193 nm) or the like, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and more preferably a structural unit (a2-1). As the structural unit (a2), one type may be contained alone, or two or more types may be used in combination.

Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).
[In the formula (a2-1),
L ^a3 represents —O— or ^* —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10. ]

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) k2 -CO-O- and is (wherein k2 is an integer from 1 to 4), more preferably Is —O—.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As a monomer which introduce | transduces structural unit (a2-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A monomer represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and represented by any one of formula (a2-1-1) to formula (a2-1-4). The monomer represented by Formula (a2-1-1) or Formula (a2-1-3) is more preferable.

  When resin (A2) contains structural unit (a2-1), the content rate is 1-45 mol% normally with respect to all the structural units of resin (A2), Preferably it is 1-40 mol%. More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

  The lactone ring contained in the structural unit (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a bridged ring including these monocyclic lactone ring structures. But you can. Among these lactone rings, a γ-butyrolactone ring or a bridged ring including a γ-butyrolactone ring structure is preferable.

  The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), or the formula (a3-3). These 1 type may be contained independently and 2 or more types may be contained.

[In the formula (a3-1),
L ^a4 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 are the same or different from each other.
In formula (a3-2),
L ^a5 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 are the same or different from each other.
In formula (a3-3),
L ^a6 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 are the same or different from each other. ]

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are each independently preferably represented by an oxygen atom or * —O— (CH ₂ ) _k3 —CO—O—. Group (k3 is an integer of 1 to 4), more preferably an oxygen atom or * —O—CH ₂ —CO—O—, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

  Examples of the monomer that leads to the structural unit (a3) include monomers described in JP 2010-204646 A. Formula (a3-1-1) to Formula (a3-1-4), Formula (a3-2-1) to Formula (a3-2-4), and Formula (a3-3-1) to Formula (a3-3) -4) is preferred, and the monomers represented by formula (a3-1-1) to formula (a3-1-2) and formula (a3-2-3) to formula (a3-2-4) are preferred. The monomer represented by either is more preferable, and the monomer represented by the formula (a3-1-1) or the formula (a3-2-3) is more preferable.

  When the resin (A-2) contains the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol, based on all the structural units of the resin (A-2). %, More preferably 10 to 60 mol%.

The resin (A-2) is preferably a resin composed of the structural unit (a) and the structural unit (s).
The structural unit (a) is preferably at least one of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably the structural unit (a1- 1).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit (a2-1). The structural unit (a3) is preferably at least one of the structural unit (a3-1) and the structural unit (a3-2).

  The resin (A-2) contains a structural unit derived from a monomer having an adamantyl group (particularly the structural unit (a1-1)) in an amount of 15 mol% or more based on the total structural unit (a). preferable. When the content of the structural unit having an adamantyl group is large, the dry etching resistance of the resist pattern is improved.

The total content of the structural unit (a) in the resin (A-2) is preferably 1 to 100 mol%, more preferably 10 to 95 mol%, based on all the structural units of the resin (A-2). More preferably, it is 15-90 mol%, Most preferably, it is 20-85 mol%.
Moreover, when resin (A-2) contains a structural unit (s), the total content rate of a structural unit (s) becomes like this. Preferably it is 5-95 mol% with respect to all the structural units of resin (A-2). More preferably, it is 10-80 mol%, More preferably, it is 20-70 mol%, Especially preferably, it is 30-70 mol%.

When resin (A-2) is resin which consists of structural unit (a) and structural unit (s), these content rates are respectively with respect to all the structural units of resin (A-2),
Structural unit (a); 10-95 mol%
Structural unit (s); 5 to 90 mol% is preferable,
Structural unit (a); 15-90 mol%
Structural unit (s); 10 to 85 mol% is more preferable,
Structural unit (a); 20 to 85 mol%
Structural unit (s); 15 to 80 mol% is more preferable,
Structural unit (a); 20-65 mol%
The structural unit (s); 35 to 80 mol% is particularly preferable.

Each structural unit constituting the resin (A-2) may be used alone or in combination of two or more, and a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. Can be manufactured by.
The weight average molecular weight of the resin (A-2) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, More preferably, it is 15,000 or less.

  In the resin (A), the content ratio (mass ratio; resin (A-1): resin (A-2)) between the resin (A-1) and the resin (A-2) is usually 0.01: 10 to 10. 5:10, preferably 0.05: 10 to 3:10, more preferably 0.1: 10 to 2:10, still more preferably 0.2: 10 to 1:10 (mass ratio) ).

<Resin other than resin (A-1) and (A-2)>
The resin (A) includes resins other than the resins (A-1) and (A-2) described above, for example, structural units derived from the acid labile monomer (a1) described above, structural units derived from an acid stable monomer. In addition, a resin having at least one selected from structural units derived from known monomers used in the field may be contained.
When resin (A) contains resin other than resin (A-1) and (A-2), the content rate of resin other than resin (A-1) and (A-2) is resin (A). It is 0.1-50 mass% normally with respect to a total amount, Preferably it is 0.5-30 mass%, More preferably, it is 1-20 mass%.

In the resist composition of the present invention, the content of the resin (A) is preferably 80% by mass or more, more preferably 99.9% by weight or less in the solid content of the resist composition. In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later.
The solid content in the composition and the content of the resin (A) relative thereto can be measured, for example, by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (II)>
The acid generator (II) is represented by the formula (II).
[In the formula (II),
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and —CH constituting the alkanediyl group ₂ — may be replaced by —O— or —CO—.
R ⁴ and R ⁵ each independently represent a hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, —CH ₂ — constituting the group may be replaced by —O— or —CO—.
Z ⁺ represents an organic cation. ]

Examples of the alkanediyl group of X ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group, butane-1,3-diyl group, 2-methylpropane -1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group and the like.
Of these, a methylene group is preferable.

Examples of the group in which —CH ₂ — constituting the alkanediyl group is replaced by —O— or —CO— include the following divalent groups. * Represents a bond with CF ₂ .

Examples of the group in which the hydrogen atom contained in the alkanediyl group is substituted with a hydroxy group or —OR ⁵ , and —CH ₂ — constituting the alkanediyl group is replaced with —O— or —CO— are, for example, Groups. * Represents a bond with CF ₂ .

The hydrocarbon group for R ⁴ and R ⁵ may be either saturated or unsaturated, for example, a linear or branched alkyl group or alkenyl group, a monocyclic or polycyclic alicyclic hydrocarbon group And an aromatic hydrocarbon group, etc., and a group formed by combining two or more of these groups may be used.
Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
Examples of the branched alkyl group include an isopropyl group, a sec-butyl group, and a tert-butyl group.
Examples of the linear or branched alkenyl group include a vinyl group and an α-methylvinyl group.
Examples of the monocyclic alicyclic hydrocarbon group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.
Examples of the polycyclic alicyclic hydrocarbon group include a norbornyl group and an adamantyl group.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, 2,6-diethylphenyl group, 2- And methyl-6-ethylphenyl.

The acid generator (II) is preferably an acid generator represented by the formula (IIA).
[In Formula (IIA), X ² and Z ⁺ represent the same meaning as described above.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and —CH ₂ constituting the hydrocarbon group -May be replaced by -O- or -CO-.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 19 or less. ]

The hydrocarbon group for R ⁶ may be either saturated or unsaturated, for example, a linear or branched alkyl group or alkenyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, aromatic carbonization A hydrogen group etc. are mentioned, The group formed by combining 2 or more types among these groups is mentioned, Preferably it is an alicyclic hydrocarbon group.
Examples of the group in which —CH ₂ — constituting the hydrocarbon group is replaced by —O— or —CO— include the following. * Represents a bond.
When R < ⁶ > is an alkyl group, Preferably it is a C1-C4 alkyl group, More preferably, it is a C2-C4 alkyl group.
Examples of the alkyl group for R ⁷ include a methyl group, an ethyl group, a propyl group, and a butyl group. Preferably it is a C1-C2 alkyl group, More preferably, it is an ethyl group.
As the fluorinated alkyl group for R ⁸ , a trifluoromethyl group, a perfluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a perfluorobutyl group, 1,1,2,2,3,3, Examples include 4,4-octafluorobutyl group, preferably a fluorinated alkyl group having 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.

Examples of the acid generator (II) include the following salts.

Examples of Z ⁺ include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, an arylsulfonium cation is more preferable, and a cation represented by any one of the formulas (b2-1) to (b2-4) [hereinafter, depending on the formula number Sometimes referred to as “cation (b2-1)”. ] Is more preferable.

In formula (b2-1) to formula (b2-4),
Each of R ^{b4 to} R ^b6 independently represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms; , R ^b4 and R ^b5 together form a ring containing a sulfur atom. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5. When m2 is 2 or more, the plurality of R ^b7 are the same or different from each other, and when n2 is 2 or more, the plurality of R ^b8 are the same or different from each other.
R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or R ^b9 and R ^b10 are combined together. Together with the sulfur atom to which they are attached, forms a 3- to 12-membered ring (preferably a 3- to 7-membered ring). —CH ₂ — constituting the ring may be replaced by —O—, —SO— or —CO—.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group has 1 to 12 carbon atoms. Or an alkoxycarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) together with —CH—CO— to which they are bonded. —CH ₂ — constituting the ring may be replaced by —O—, —SO— or —CO—.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b24 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 are the same or different from each other. When p2 is 2 or more, the plurality of R ^b14 are the same or different from each other. When q2 is 2 or more, the plurality of R ^b15 are the same. Alternatively, when r2 is 2 or more, a plurality of R ^b16 are the same or different from each other, when s2 is 2 or more, a plurality of R ^b17 are the same or different from each other, and when t2 is 2 or more, a plurality of R ^{b16 b18} are the same or different from each other.

R ^b4 and R ^b5 may together form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with the sulfur atom to which they are bonded.

Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2- An ethylhexyl group is mentioned. In particular, the aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
Examples of the alkyl group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.
In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 4 to 12 carbon atoms.

  Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group, and an isobornyl group. Can be mentioned.

Examples of the aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-adamantyl group. Substituted or unsubstituted phenyl groups such as phenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group; biphenylyl group, naphthyl group, phenanthryl group and the like.
As an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group, 4-methoxyphenyl group etc. are mentioned, for example.
Examples of the alkyl group in which a hydrogen atom is substituted with an aromatic hydrocarbon group, that is, an aralkyl group, include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.
In addition, when an alkyl group or an alicyclic hydrocarbon group is contained in an aromatic hydrocarbon group, a C1-C12 alkyl group and a C3-C18 alicyclic hydrocarbon group are preferable.

Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group. Group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.

The ring containing a sulfur atom which may be formed by combining R ^b4 and R ^b5 is any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. As long as it contains one or more sulfur atoms, it may further contain one or more oxygen atoms. As the ring, a ring having 3 to 18 carbon atoms is preferable, and a ring having 4 to 18 carbon atoms is more preferable.

Examples of the ring formed together with the sulfur atom to which R ^b9 and R ^b10 are bonded include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium. A ring etc. are mentioned.
Examples of the ring formed with —CH—CO— in which R ^b11 and R ^b12 are bonded include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cation (b2-1) to cation (b2-4), the cation (b2-1) is preferable, more preferably a cation represented by the formula (b2-1-1) (hereinafter referred to as “cation ( more preferably triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (formula ( b2-1-1), v2 = w2 = 0, x2 = 1, R ^b21 is a methyl group) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1 and R ^b19 , R ^b20 and R ^b21 are all methyl groups).

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 3 to 18 carbon atoms. Represents an alicyclic hydrocarbon group. It is also possible that two selected from R ^b19 to R ^b21 together form a ring containing a sulfur atom.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, the plurality of R ^b19 are the same or different from each other. When w2 is 2 or more, the plurality of R ^b20 are the same or different from each other. When x2 is 2 or more, the plurality of R ^b21 are the same. Or different.

Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. It is.

  Specific examples of the cation represented by the formula (b2-1-1) include cations described in JP 2010-204646 A.

  The acid generator (II) is a combination of the above anion and the above cation. These can be arbitrarily combined, and among them, the salt represented by the following is preferable.

The salt (II) can be obtained, for example, by reacting a salt represented by the formula (II-0-1) with a compound represented by the formula (II-0-2) in a solvent. Examples of the solvent include chloroform.
[Wherein, X ² , R ⁴ and Z ⁺ represent the same meaning as described above. ]
The salt represented by the formula (II-0-1) can be obtained, for example, according to the method described in US2007 / 298352A1.

Examples of the salt represented by the formula (II-0-1) include salts represented by the following.

The compound represented by the formula (II-0-2) is obtained by reacting a salt represented by the formula (II-0-3) and a compound represented by the formula (II-0-4) in a solvent. Can be obtained.
Examples of the solvent include chloroform.
[Wherein R ⁴ represents the same meaning as described above. ]
Examples of the compound represented by the formula (II-0-3) include compounds represented by the following.

The salt represented by the formula (IIA) can be obtained, for example, by reacting the salt represented by the formula (IIA-1) with the compound represented by the formula (IIA-2) in a solvent. Examples of the solvent include chloroform.
[Wherein, X ² , R ⁶ , R ⁷ , R ⁸ and Z ⁺ represent the same meaning as described above. ]

The salt represented by the formula (IIA-1) is obtained by reacting the salt represented by the formula (II-0-1) and the compound represented by the formula (IIA-4) in a solvent in the presence of an acid catalyst. Can be manufactured. Examples of the solvent include dimethylformamide. Examples of the acid catalyst include p-toluenesulfonic acid.
[Wherein, X ² , R ⁷ , R ⁸ and Z ⁺ represent the same meaning as described above. ]
Examples of the compound represented by the formula (IIA-4) include ethyl trifluoropyruvate.

The compound represented by the formula (IIA-2) can be obtained by reacting the salt represented by the formula (IIA-5) and the compound represented by the formula (IIA-6) in a solvent. .
Examples of the solvent include chloroform.
[Wherein R ⁶ represents the same meaning as described above. ]
Examples of the compound represented by the formula (IIA-5) include compounds represented by the following.

  The salt (II) may be used alone or in combination of two or more.

<Acid generator other than salt (II)>
The resist composition may contain an acid generator other than the acid generator (II) described above (hereinafter sometimes referred to as “acid generator (B)”).
The acid generator (B) may be either nonionic or ionic. Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712 The compound which generate | occur | produces an acid by the radiation as described in etc. can be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “salt (B1)”).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — constituting the saturated hydrocarbon group may be replaced by —O— or —CO—. .
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — constituting the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z1 ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group for Q ^b1 and Q ^b2 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, A perfluorohexyl group etc. are mentioned.
Q ^b1 and Q ^b2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

The divalent saturated hydrocarbon group of L ^{b1 includes} a divalent aliphatic saturated carbon group such as a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, etc. A hydrogen group may be mentioned, and a group formed by combining two or more of these groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- Branched alkanediyl groups such as diyl groups;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which —CH ₂ — constituting the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include any of formulas (b1-1) to (b1-7) The group represented by these is mentioned. L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), more preferably a group represented by formula (b1-1) or formula (b1-2), More preferably, it is group represented by Formula (b1-1). In addition, Formula (b1-1)-Formula (b1-7) have described the right and left according to Formula (B1), and among two bonds represented by *, C (Q ^b1 ) binds to (Q ^b2 )-, and binds to -Y on the right. Specific examples of the following formulas (b1-1) to (b1-7) are also described in accordance with the formula (B1) on the left and right sides, and each of the two bonds represented by * is represented by C on the left side. It binds to (Q ^b1 ) (Q ^b2 ) — and on the right side to —Y.

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b6 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b5 and L ^b6 is 15.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b7 and L ^b8 is 16.
L ^b9 represents a single bond or a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b10 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 14.
L ^b11 and L ^b12 each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b11 , L ^b12 and L ^b13 is 12.
L ^b14 and L ^b15 each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 14.

Examples of the group represented by the formula (b1-1) include the following.

Examples of the group represented by the formula (b1-2) include the following.

Examples of the group represented by the formula (b1-3) include the following.

Examples of the group represented by the formula (b1-4) include the following.

Examples of the group represented by the formula (b1-5) include the following.

Examples of the group represented by the formula (b1-6) include the following.

Examples of the group represented by the formula (b1-7) include the following.

Examples of the alkyl group for Y include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl group, 2 -Alkyl groups, such as an ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, are mentioned, Preferably a C1-C6 alkyl group is mentioned.
Examples of the alicyclic hydrocarbon group include groups represented by formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — constituting the alicyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— are represented by formulas (Y12) to (Y26). Groups.

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent of the alkyl group and alicyclic hydrocarbon group in Y include, for example, a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, carbon C3-C16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl group , Glycidyloxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or carbon Represents an aromatic hydrocarbon group of formula 6 to 18. j2 represents an integer of 0 to 4).

Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.

In the case where Y is an alkyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y. The group —CH ₂ — is preferably replaced by —O— or —CO—. In this case, —CH ₂ — constituting the alkyl group of Y is not replaced by —O— or —CO—. Even when a hydrogen atom contained in the alkyl group of Y and / or the divalent linear or branched saturated hydrocarbon group of L ^b1 is substituted with a substituent, —CH ₂ — constituting the alkyl group of Y Is not replaced by —O— or —CO—.

  Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably a substituent (for example, an oxo group, a hydroxy group, etc.). A good adamantyl group, more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

The sulfonate anion in the salt (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9). In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt (B1) include anions described in JP 2010-204646 A.

Examples of the organic cation (Z1 ⁺ ) contained in the salt (B1) include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. An organic sulfonium cation or an organic iodonium cation, more preferably an arylsulfonium cation, and still more preferably a cation represented by any one of the formulas (b2-1) to (b2-4) described above.

  Examples of the salt (B1) include salts represented by the formula (B1-1) to the formula (B1-20). Among them, those containing a triphenylsulfonium cation or a tolylsulfonium cation are preferable, and are represented by the formula (B1-1), the formula (B1-2), the formula (B1-3), the formula (B1-6), and the formula (B1-7). And a salt represented by any one of the formulas (B1-11), (B1-12), (B1-13) and (B1-14).

When the resist composition contains only the acid generator (II) as the acid generator, the content of the acid generator (II) is preferably 1 part by mass or more with respect to 100 parts by mass of the resin (A) ( More preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass or less).
When the resist composition contains the acid generator (II) and the acid generator (B), the total content of the acid generator (II) and the acid generator (B) is 100 masses of the resin (A). The amount is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less).
The content ratio (mass ratio) between the acid generator (II) and the acid generator (B) is, for example, 5:95 to 95: 5, preferably 10:90 to 90:10, and more preferably 15: 85-85: 15.

<Compound (D)>
Compound (D) is represented by formula (D).
[In the formula (D),
R ^1d and R ^2d are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
md and nd each independently represent an integer of 0 to 4. When md is 2 or more, the plurality of R ^1d are the same or different, and when nd is 2 or more, the plurality of R ^2d are the same or different. . ]

In the compound (D), examples of the hydrocarbon group of R ^1d and R ^2d include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. It is done.
Examples of the aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, and nonyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be either saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, and cyclododecyl group, norbornyl group, adamantyl group, and the like.
As aromatic hydrocarbon group, phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group , Aryl groups such as mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the group formed by combining these include alkyl-cycloalkyl group, cycloalkyl-alkyl group, aralkyl group (for example, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1 -Propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6 -Phenyl-1-hexyl group, etc.).

Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group.
Examples of the acyloxy group include a group in which an oxy group (—O—) is bonded to the acyl group.
Examples of the alkoxycarbonyl group include a group in which a carbonyl group (—CO—) is bonded to the above alkoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

In the formula (D), R ^1d and R ^2d are each independently an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or 2 to 4 carbon atoms. And an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom is preferable.
md and nd are each independently preferably an integer of 0 to 2, and more preferably 0. When md is 2 or more, the plurality of R ^1d are the same or different, and when nd is 2 or more, the plurality of R ^2d are the same or different.

Examples of the compound (D) include the following compounds.

  Compound (D) can be produced by the method described in “Tetrahedron Vol. 45, No. 19, p6281-6296”. Moreover, the compound (D) can use the compound marketed.

  The content of the compound (D) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably about 0.1 to 5% by mass in the solid content of the resist composition. It is about 01 to 1% by mass.

<Solvent (E)>
The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example 99.9% by mass or less, preferably 99% by mass or less. It is. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent may contain individually by 1 type and may contain 2 or more types.

<Basic compound (C)>
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by any one of the formulas (C1) to (C8) and (C1-1), more preferably represented by the formula (C1-1). The compound which is made is mentioned.

[In formula (C1), R ^c1 , R ^c2 and R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or 6 to 6 carbon atoms. 10 represents an aromatic hydrocarbon group, and the hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms, The hydrogen atom contained in the aromatic hydrocarbon group is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms. It may be substituted with a group hydrocarbon group. ]

[In Formula (C1-1), R ^c2 and R ^c3 represent the same meaning as described above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 are the same or different from each other. ]

[In Formula (C2), Formula (C3) and Formula (C4), R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different from each other. ]

[In Formula (C5) and Formula (C6), R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3, and when o3 is 2 or more, the plurality of R ^c14 are the same or different from each other, and when p3 is 2 or more, the plurality of R ^c15 are the same as each other Or different.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are the same or different from each other, and when r3 is 2 or more, the plurality of R ^c19 are When s3 is 2 or more, the plurality of R ^c20 are the same or different from each other.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, and pentyl group.
The alicyclic hydrocarbon group in the formula (C1), the formula (C5) to the formula (C8) and the formula (C1-1) includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexyl. Cycloalkyl groups such as a group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group.
Examples of the alicyclic hydrocarbon group in the formulas (C2) to (C4) include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
A phenyl group etc. are mentioned as an aromatic hydrocarbon group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group.
Examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane- 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, cyclobutane A -1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group and the like can be mentioned.
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

  Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl. Piruanirin. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipiconylamine, bipyridine and the like.

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

  The content of the basic compound (C) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably in the solid content of the resist composition. It is about 0.01-1 mass%.

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition may contain other components (F) as necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, and the like can be used.

<Preparation of resist composition>
Resist composition includes resin (A) and acid generator (II), and compound (D), solvent (E), acid generator (B), basic compound (C) and others used as necessary. It can prepare by mixing the component (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to the solvent (E), such as a kind, etc. of resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) A step of applying the resist composition of the present invention on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) The process of heating the composition layer after exposure, (5) The process of developing the composition layer after a heating is included.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater.

The composition layer is formed by drying the composition after application. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or using a decompression device. The heating temperature is preferably 50 to 200 ° C., for example, and the heating time is preferably 10 to 180 seconds, for example. The pressure during drying under reduced pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) using various types of laser light such as those that convert the wavelength of laser light from the laser to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, those that irradiate an electron beam or extreme ultraviolet light (EUV), etc. it can.

  The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction of the resin (A). As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer. Examples of the solvent different from the organic developer include alcohols such as 4-methyl-2-pentanol and isopropanol.

It is preferable to wash the developed resist pattern with a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly a liquid. It is suitable as a resist composition for immersion exposure and useful for fine processing of semiconductors.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing the content and the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

Resin synthesis Monomers used for resin synthesis are shown below.
Hereinafter, these monomers are referred to as “monomer (a1-1-1)” or the like according to the formula number.

Synthesis Example 1 [Synthesis of Resin A1]
As the monomer, the monomer (a1-1-3), the monomer (a1-2-9), the monomer (a2-1-3), the monomer (a3-2-3) and the monomer (a4-1) are used and their moles are used. The ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3) :( a4-1)] is 45: 14: 2. 5: 22.5: 16, and 1.5 mass times the total amount of dioxane was added to form a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 8.8. A × 10 ³ resin A1 (copolymer) was obtained with a yield of 71%. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin A2]
As the monomer, using monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-2-3)): monomer (a3-1-1)] However, it mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin obtained was dissolved again in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight-average molecular weight was 7. 9 × 10 ³ resin A2 (copolymer) was obtained in a yield of 73%. This resin A2 has the following structural units.

Synthesis Example 3 [Synthesis of Resin A3]
As the monomer, monomer (a1-1-1), monomer (a2-1-1) and monomer (a3-1-1) were used, and their molar ratio [monomer (a1-1-1): monomer (a2-1) -1): monomer (a3-1-1)] was mixed at 35:25:40, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol solvent to precipitate the resin, and the resin was filtered. The resin obtained was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 8. 7 × 10 ³ resin A3 (copolymer) was obtained with a yield of 90%. This resin A3 has the following structural units.

Synthesis Example 4 [Synthesis of Resin H1]
Monomer (I-1) and monomer (a1-2-9) are used as monomers and mixed so that the molar ratio [monomer (I-1): monomer (a1-2-9)] is 50:50. Then, 1.2 mass times the total monomer amount of methyl isobutyl ketone was added to make a solution. To the solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added in an amount of 3 mol% based on the total monomer amount, and these were heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin. Resin H1 (copolymer) having an average molecular weight of 9.0 × 10 ³ was obtained in a yield of 85%. This resin H1 has the following structural units.

Synthesis Example 5 [Synthesis of Resin H2]
Monomer (a4-z) was used as a monomer, and 4.0 mass times propylene glycol monomethyl ether acetate as a total monomer amount was added to prepare a solution. To the solution, 8 mol% of V-601 (manufactured by Wako Pure Chemical Industries) as an initiator was added with respect to the total amount of monomers, and these were heated at 80 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin. Resin H2 having an average molecular weight of 7.6 × 10 ³ was obtained with a yield of 70%. This resin H2 has the following structural units.

Synthesis Example 6 [Synthesis of Resin H3]
Monomer (I-2) and monomer (a1-2-9) are used as monomers and mixed so that the molar ratio [monomer (I-2): monomer (a1-2-9)] is 50:50. Then, 1.2 mass times the total monomer amount of methyl isobutyl ketone was added to make a solution. To the solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added in an amount of 3 mol% based on the total monomer amount, and these were heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin. Resin H1 (copolymer) having an average molecular weight of 9.1 × 10 ³ was obtained in a yield of 87%. This resin H3 has the following structural units.

Synthesis Example 7 [Synthesis of Resin H4]
Monomer (I-1) and monomer (a1-1-1) are used as the monomers and mixed so that the molar ratio [monomer (I-1): monomer (a1-1-1)] is 50:50. Then, 1.2 mass times the total monomer amount of methyl isobutyl ketone was added to make a solution. To the solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added in an amount of 3 mol% based on the total monomer amount, and these were heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin. Resin H1 (copolymer) having an average molecular weight of 9.4 × 10 ³ was obtained in a yield of 83%. This resin H4 has the following structural units.

<Preparation of resist composition>
As shown in Table 1, each component was mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1: Resin A1
A2: Resin A2
A3: Resin A3
H1: Resin H1
H2: Resin H2
H3: Resin H3
H4: Resin H4

<Acid generator>
II-2: Central Glass
B1-3: synthesized according to the example of JP 2010-152341 A
Z1:

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)
<Compound (D)>
D1: (Tokyo Chemical Industry Co., Ltd.)
<Solvent>
Propylene glycol monomethyl ether acetate 250 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

Examples 1 to 10 and Comparative Example 1
<Manufacture of negative resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer, and baked under the conditions of 205 ° C. and 60 seconds, whereby an organic layer having a thickness of 78 nm was obtained. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after pre-baking was 110 nm. After coating, the composition layer was formed on the silicon wafer by pre-baking on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 1. An ArF excimer laser stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annular illumination, x, y-polarized light) is applied to the composition layer formed on the silicon wafer with a hole pattern (pitch Using a mask for forming (120 nm / hole diameter 55 nm), exposure was carried out by changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium. After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

<Resolution evaluation and effective sensitivity>
The obtained resist pattern was observed with a scanning electron microscope. If the 55 nm hole pattern was resolved, it was marked as ◯, and if not resolved, it was marked as x. Here, “resolution” means that the hole pattern obtained using the mask can be formed without blocking.
The exposure amount at which the hole pattern diameter was 55 nm was defined as effective sensitivity.
The results are shown in Table 2.

<Focus margin (DOF) evaluation>
A negative resist pattern was manufactured in the same manner as described above except that the exposure was performed while changing the focus stepwise in terms of effective sensitivity. In the obtained resist pattern, the focus range in which the diameter of the hole pattern is 55 nm ± 10% (60.5 to 49.5 nm) was defined as DOF (nm). The results are shown in Table 2.

<Evaluation of CD uniformity (CDU)>
A negative resist pattern was manufactured in the same manner as described above except that a mask for forming a hole pattern having a pitch of 120 nm and a hole diameter of 60 nm was used in terms of effective sensitivity. In the obtained resist pattern, the hole diameter was measured 24 times per hole, and the average value was taken as the average hole diameter of one hole. A standard deviation was determined using a population of 105 measured average hole diameters of resist patterns in the same wafer. The results are shown in Table 2.

  From the above results, it can be seen that according to the resist composition of the present invention, a resist pattern with excellent resolution can be produced.

  According to the resist composition of the present invention, a high-resolution resist pattern can be obtained.

Claims (3)

A resin containing a structural unit represented by formula (I),
Includes a structural unit having an acid labile group, tree does not include a structural unit represented by formula (I) fat,
An acid generator represented by the formula (IIA) and
A resist composition containing an acid generator represented by the formula (B1) .
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² represents a saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom. ]
[In the formula (IIA)
X ² represents an alkanediyl group having 1 to 6 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a hydroxy group or —OR ⁵ , and —CH constituting the alkanediyl group ₂ — may be replaced by —O— or —CO—.
R ⁵ represents a hydrocarbon group having a carbon number of 1 to 24, hydrogen atoms contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, -CH ₂ constituting the hydrocarbon group -May be replaced by -O- or -CO-.
R ⁶ represents a hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and —CH ₂ constituting the hydrocarbon group -May be replaced by -O- or -CO-.
R ⁷ represents an alkyl group having 1 to 6 carbon atoms.
R ⁸ represents a fluorinated alkyl group having 1 to 6 carbon atoms.
However, the total carbon number of R ⁶ , R ⁷ and R ⁸ is 19 or less. ]
Z ⁺ represents an organic cation. ]
[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — constituting the saturated hydrocarbon group may be replaced by —O— or —CO—. .
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — constituting the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z1 ⁺ represents an organic cation. ] A resist composition according to claim 1, further comprising a solvent. (1) The process of apply | coating the resist composition of Claim 1 or 2 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including: